A bit less spammy dependabot config

.github/dependabot.yml

@@ -3,5 +3,7 @@ updates:
 - package-ecosystem: nuget
   directory: "/"
   schedule:
-    interval: daily
+    interval: monthly
   open-pull-requests-limit: 10
+  ignore:
+    - dependency-name: "LibreHardwareMonitorLib"